Barrett Tillman, the "mad scientist of sour beer" at Deep Ellum Brewing Co., stopped by the Old Monk to chat with Tim and Zac about how he got into the beer-making business — and to offer samples of his wares.

Hosts: Tim Rogers, Zac CrainTheme music: Shibboleth's "The Bavarian," from the 2008 album Experiment in Error (Idol Record